Production of polymerization products from isobutylene



Patented Dec. 22, 1936 r UNITED STATES PATENT or'F-lcs I PRODUCTION OFPOLYMERIZATIOIN PRODUCTS FROM ISOBUTYLENE Martin Mueller-Cunradi and Michael Otto, Lud wigshaien-on-the-Rhine, Germany, assignors to I. G. Farbenindustrle Aktien'gesellschai't, Frankfort-on-the-Main, Germany 7 No Drawing. Application January -25, 1934,

Serial No. 708,256. In Germany January 28,

Claims.

The present invention relates to the production of polymerization products from isobutylene."

It has been proposed by us in our copending 5 application Serial No. 623,812 to produce hydrocarbons of high molecular weight by the polymerization of isobutylene in the presence of volatile inorganic halides, i. e. of catalysts of the Friedel-Crafts type, such as boron fluoride, phosphorus trior pentafluoride, or aluminium chloride; while continuously keeping, until the completion oi. the reaction by strong cooling, the reacting materials at.low temperatures, as for example lower than '10 below zero centigrade. -Mixtures which contain isobutylene and also, for example, oleflnes, may be employed instead of isobutylene. v y We have now found that mixtures of the said kind can also be converted into valuable polymerization products of isobutylene at temperatures between 10 below zero and 100 C., for example at ordinary (i. e. room) or still more elevated temperatures by exposing the mixtures to the action of volatile inorganic halides for so short a time only that substantially only the isothis way are generally speaking not of such high molecular weight as those obtainable at substantially lower temperatures. Products are obtained.

for example having the character of light to heavy mineral oils. The products, especially when employing boron fluoride as the polymerization catalyst, may be split up again by heating into isobutylene or dimeric or trimeric compounds of isobutylene. The process according to this invention thus renders it possible to obtain isobutylene or polymers thereof of low molecular weight in a pure form from mixtures of gases or liquids containing isobutylene, and these pure Emmple 1 A mixture of lpart of isobutylene and 2.5 parts of normal butylene is caused to flow under a pressure of from 3 to 5 atmospheres and at ordinary (i. e. room) temperature while cooling 'Raschig rings and provided with a water, cooling placket. Boron fluoride is present in the tube 5 under a partial pressure or about 0.25 atmosbutylene is polymerized. Products obtained in The parts are strongly with water through a tube filled with phere. If the said mixture be led so rapidly through the tube that it is only exposed to the action .of' the boron fluoride for about 1 minute,

practically only the isobutylene is polymerized.

- Per cent Boiling up to 100 C 4 Boiling up to 200 C. 47 Boiling up to 150 C. (15 millimeters) 71 Boiling up to 200 C. (0.06 millimeter) 83 Residue 11 Loss 6 If this oil be distilled at between 300 and 400 C. over catalysts, such as active carbon or bleaching earths containlng'phosphoric acid, it is spli up again into isobutylene.

Example 2 100 grams of isobutylene and 300 grams of normal butylene are shaken in an autoclave at C. with 20 grams oi titanium tetrachloride for about half an hour. By releasing the pressure 290 grams of normal butylene containing 4.5 per cent of isobutylene. escape. 95 grams of an oil remain having the ciinsistency of a lubri eating oil.

-- Example 3 30 grams of isobutylene and '70 grams of normal butylene are stirred for 3 minutes atzero C with 3 grams of aluminium chloride. Water isv then added for decomposing the aluminium chloride and themass is distilled. 15 grams of an oil formed mainly from isobutylene are obtained, whereas the normal butylene occurs as such in the distillate.

Whatwe claim is:

1. The process of selectively polymerizing iso- -'butylene from mixtures containing isobutylene which comprises reacting such a mixture comprising isobutylene and at least one other oleflne with a volatile inorganic halide catalyst oi'the- Frieda-Crafts type at a temperature above 10 "below zero 0, but below 100 0., for a sufliciently short time, that substantially only the isobutylene is polymerized. I I 2.v The process oi! selectivelypoiymerizing isobutylene from mixtures containing isobutylene which comprises reacting such a mixture comprising isobutylene and at least one other oleflne with boron fluoride at a temperature above 10 below zero 0, but below 100 C., for a sufficiently short time, that substantially only the isobutylene is polymerized.

3. The process of selectively polymerizing isobutylene from mixtures containing isobutylene which comprises reacting such a mixture comprising isobutylene and at least one other oleflne v with a volatile inorganic halide catalyst of the Friedel-Crafts type at about room temperature for a sufliciently short time, that substantially only the isobutylene is polymerized. I

4. The process of selectively polymerizing isobutylene from mixtures containing isobutylene which comprises reacting sucha mixture comprising isobutylene and at least one other olefln'e with boron fluoride at about room temperature for a sufficiently short time, that substantially only the isobutylene is polymerized.

5. The process of separating isobutylene from normal butylene by selective polymerization which comprises reacting a mixture consisting oi isobutylene and normal butylene with a volatile inorganic halide catalyst of the Friedel-Crafts type at a temperature above 10 below zero C., but below 100 0., for a sufilciently short time, that substantially only the isobutylene is polymerized.-

- MARTIN MUELLER-CUNRADI.

MICHAEL OTIO. 

